package com.ithuaxin.comprehensiveractice;

import javax.xml.transform.Result;
import java.util.Random;

public class Test4 {
    public static void main(String[] args) {
        char arr[] = new char[52];
        String result = "";
        Random r = new Random();
        for (int i = 0; i < arr.length; i++) {
            if (i<=25){
                arr[i] = (char) (65 + i);
            }
            else{
                arr[i] = (char) (97 + i - 26);
            }
        }
        for (int i = 0; i < 4; i++) {
            int randomIndex = r.nextInt(52);
            result = result + arr[randomIndex];
        }
        int num = r.nextInt(10);
        result = result + num;
        System.out.println(result);
    }
}
